诱导型一氧化氮合酶在人皮肤自然衰老过程中的表达和意义

目的:探讨诱型一氧化氮合酶(iNOS)与人皮肤自然衰老的关系.方法:收集整形外科植皮手术中非曝光部位的皮肤标本60例,采用反转录(RT)-PCR和免疫组化的方法检测皮肤组织中iNOS的表达水平,根据年龄分为青少年组、中年组和老年组3组,分析不同年龄组之间iNOS表达水平的差异.结果:青少年组、中年组和老年组iNOS mRNA表达的相对量分别为0.372 7±0.037 1、0.601 4±0.052 5和0.711 0±0.050 7,3组之间的差异具有统计学意义(P＜0.05);免疫组化示iNOS蛋白在青少年组主要为低度阳性,中年组主要为中度阳性.老年组主要为中高度阳性,3组之间的差异亦具有统计学意义(P＜0.05).结论:iNOS在皮肤组织中的表达量随年龄增长而增多,其可能与人皮肤的自然衰老有密切关系.     

过氧化物酶体增殖激活物受体γ在皮肤自然衰老过程中的表达及意义

目的研究过氧化物酶体增殖激活物受体γ（PPARγ）在皮肤自然衰老过程中的表达及其意义。方法采用免疫组化方法（SP法）检测PPARγ的蛋白表达水平，RT—PCR方法检测PPARγ的mRNA表达水平。结果免疫组化研究结果表明中老年组PPARγ蛋白的表达强度显著高于青少年组（x^2=15．48，P=0．001）；RT—PCR检测结果表明中老年组PPARγmRNA的平均表达水平为0．697±0．204，青少年组为0．337±0．124，中老年组亦显著高于青少年组（t=8．25，P〈0．001）。结论随着年龄的增加，皮肤PPARγ的表达增高，在皮肤自然老化过程中可能起重要作用，PPARγ有可能成为研制延缓皮肤自然衰老药物的新靶点。     

皮肤自然衰老及光老化

皮肤的光老化和自然衰老是两个既有联系又有各自不同临床表现和发病机制的过程。皮肤的自然衰老是一个自然发生而不易改变的过程 ,而光老化则是可以通过有效预防和治疗改善的。文中就皮肤的自然衰老和光老化从影响因素、发生机制、临床表现及预防、治疗等方面加以阐述     

SIRT1与皮肤衰老的相关性

沉默信息调节因子2相关酶1(SIRT1)是烟酰胺腺嘌呤二核苷酸(NAD)+依赖的组蛋白去乙酰化酶,可使多种蛋白的赖氨酸残基脱去乙酰基。近年来的研究表明,SIRT1可通过其去乙酰化作用来调节蛋白质的功能,并具有抗衰老作用。本文就SIRT1与皮肤衰老可能的关系做一综述,以期能为皮肤衰老治疗的研究提供新的方向。     

Pinx1、hTERT mRNA在三种皮肤肿瘤组织中的表达及意义

目的 探讨内源性端粒酶抑制基因PinX1及端粒酶逆转录酶hTERT在基底细胞癌、鳞状细胞癌、日光性角化病组织中的表达及其意义。 方法 实时定量PCR检测实验组36例3种皮肤肿瘤组织中内源性端粒酶抑制基因PinX1及端粒酶逆转录酶hTERT的mRNA表达水平,并以15例正常人皮肤组织作为对照组。 结果 实验组PinX1基因的mRNA表达水平（2.53 ± 1.57）低于对照组（4.25 ± 2.02）,差异有统计学意义（t = 3.273,P < 0.05）;hTERT基因的mRNA表达水平（6.37 ± 3.81）明显高于对照组（1.62 ± 0.99）,差异有统计学意义（t = 6.927,P < 0.05）;Pinx1的表达水平与hTERT表达的相关性无统计学意义（P > 0.05）。 结论 PinX1的下调及hTERT上调可能与3种皮肤肿瘤形成过程中端粒酶激活及维持机制有关。     

昼夜节律在皮肤衰老中的研究进展

昼夜节律也称生物钟,约为24 h。它由中央振荡器和外周振荡器组成,并且由节律基因形成的转录翻译反馈环来调节。皮肤受中央振荡器控制,受褪黑素分泌的影响,同时具有自主节律。皮肤角质形成细胞、黑素细胞、成纤维细胞都具有昼夜节律。UV和蓝光都能引起皮肤衰老,衰老的皮肤干燥缺水、胶原流失、皱纹横生、布满斑点,毛发变白和脱落。目前的研究表明,皮肤衰老病理机制(活性氧积聚、DNA损伤、基质金属蛋白酶上调、水合异常、黑色素沉积、MAPK和cAMP途径激活)可能和节律基因异常表达有关。本文将对昼夜节律和皮肤衰老相关研究进行简要综述。     

GLUT-1、Ki-67在皮肤肿瘤中的表达及意义

目的：探讨葡萄糖转运蛋白-1（GLUT-1）在脂溢性角化病（SK）、日光性角化病（AK）、Bowen病（BD）、鳞状细胞癌（SCC）中的表达及其与细胞增殖因子Ki-67之间的关系。方法：采用免疫组化法检测了95例不同皮肤肿瘤GLUT-1及Ki-67的表达。结果：GLUT-1及Ki-67在SK及正常皮肤都不表达,在AK、BD及SCC表达上调,并且二者的阳性表达强度间具有正相关性。结论：GLUT-1在恶性皮肤肿瘤中表达上调,与肿瘤的侵袭和转移有关。其表达强度可作为判断皮肤肿瘤恶性程度的检测指标,对诊断及鉴别诊断具有参考价值。     

FoxO转录因子在皮肤创伤修复及瘢痕演变中的作用

叉头框(forkhead box, Fox)转录因子中的FoxO亚家族(FoxO1、FoxO3a、FoxO4和FoxO6)广泛存在于真核细胞中,在细胞增殖、凋亡、代谢、衰老、氧化应激和自噬等方面发挥重要作用。FoxO转录因子通过参与调控皮肤炎症、血管生成、再上皮化和组织重塑,在创伤修复及瘢痕演变过程中起着至关重要的作用。本综述结合FoxO的一般生物学特性着重探讨其在皮肤创伤修复及瘢痕形成的最新进展。     

芳香烃受体在皮肤外源性衰老中的研究进展

芳香烃受体(aryl hydrocarbon receptor,AHR)是一种在皮肤细胞中表达的核转录因子,可介导多环芳烃类化合物(polycyclic aromatic hydrocarbons,PAH)的细胞毒性反应,在皮肤细胞的分化增殖发挥重要作用,继而产生对皮肤细胞衰老、凋亡等方面的影响.外源性污染物主要是通过...     

Biology of estrogens in skin: implications for skin aging

Estrogens have a profound influence on skin. The relative hypoestrogenism that accompanies menopause exacerbates the deleterious effects of both intrinsic and environmental aging. Estrogens clearly have a key role in skin aging homeostasis as evidenced by the accelerated decline in skin appearance seen in the perimenopausal years. Estrogens improve skin in many ways. Among these, they increase collagen content and skin thickness and improve skin moisture. However, despite the knowledge that estrogens have such important effects on skin, the cellular and subcellular sites and mechanisms of estrogen action are still poorly understood. Estrogen receptors (ERs) have been detected in skin, and recent studies suggest that estrogens exert their effect in skin through the same molecular pathways used in other non-reproductive tissues. Although systemic hormone replacement therapy (HRT) has been used for many years, recent trials have reported a significant increased risk of breast cancer and other pathologies with this treatment. This has led to reconsider the risks and benefits of HRT. For this reason, systemic HRT cannot be recommended today to treat skin aging. Currently, intensive research is conducted to develop new drugs called selective ER modulators (SERMs). These drugs exert mixed estrogenic and antiestrogenic effects depending on the tissue and cell type. One might expect in the future such a drug targeting specifically the skin without systemic side effects.     

Elderly skin and its rejuvenation: products and procedures for the aging skin

In the last few decades, there has been a substantial increase in the population of people over 60 years of age. Most of them maintain a good general health and physical activity and fitness. For these individuals there is a good number of dermatologic procedures, medications, and cosmetics that can be prescribed to improve the aspect of skin aging, providing an improvement in their self-esteem and quality of life as a result of their better look. We will discuss the mechanisms of skin aging, and the procedures and substances used to minimize its deleterious effects, such as sunscreens, estrogens, chemical peels, toxin botulinum, fillers and surgical procedures, among others. The use of makeup and the adverse reactions to cosmetics will also be mentioned.     

Skin texture parameters of the dorsal hand in evaluating skin aging in China

Background/purpose: There are various non‐invasive methods in skin morphology for assessing skin aging. The use of digital photography will make it easier and more convenient. In this study, we explored some skin texture parameters for evaluating skin aging using digital image processing. Methods: Two hundred and twenty‐eight subjects who lived in Sanya, China, were involved. Individual sun exposure history and other factors influencing skin aging were collected by a questionnaire. Meanwhile, we took photos of their dorsal hands. Skin images were graded according to the Beagley–Gibson system. These skin images were also processed using image analysis software. Five skin texture parameters, Angle Num., Angle Max., Angle Diff., Distance and Grids, were produced in reference to the Beagley–Gibson system. Results: All texture parameters were significantly associated with the Beagley–Gibson score. Among the parameters, the distance between primary lines (Distance) and the value of angle formed by intersection textures (Angle Max., Angle Diff.) were positively associated with the Beagley–Gibson score. However, there was a negative correlation between the number of grids (Grids), the number of angle (Angle Num.) and the Beagley–Gibson score. These texture parameters were also correlated with factors influencing skin aging such as sun exposure, age, smoking, drinking and body mass index. In multivariate analysis, Grids and Distance were mainly affected by age. But Angle Max. and Angle Diff. were mainly affected by sun exposure. Conclusion: It seemed that the skin surface morphologic parameters presented in our study reflect skin aging changes to some extent and could be used to describe skin aging using digital image processing.